the engine you are trying to use is OBD-0
your car is OBD-1
the ECU you are trying to use is OBD-1
the ECU is going to look for a lot of sensors and shit that the engine doesnt have ... so its going to be a bitch to get it running right

that engine also comes with a cable tranny your car has a hydro tranny

it is also illegal in most places to put an engine in the car that is older than the car

I believe that hasport sells teh correct tranny mount for the cable tranny's and you will also need to get a CRX pedal box, and the cable for that 91 ls tranny. Not sure on ecu. I believe that we have a ecu guide under the reference page.